1/*
2  A trivial static http webserver using Libevent's evhttp.
3
4  This is not the best code in the world, and it does some fairly stupid stuff
5  that you would never want to do in a production webserver. Caveat hackor!
6
7 */
8
9/* Compatibility for possible missing IPv6 declarations */
10#include "../util-internal.h"
11
12#include <stdio.h>
13#include <stdlib.h>
14#include <string.h>
15
16#include <sys/types.h>
17#include <sys/stat.h>
18
19#ifdef _WIN32
20#include <winsock2.h>
21#include <ws2tcpip.h>
22#include <windows.h>
23#include <getopt.h>
24#include <io.h>
25#include <fcntl.h>
26#ifndef S_ISDIR
27#define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR)
28#endif
29#else /* !_WIN32 */
30#include <sys/stat.h>
31#include <sys/socket.h>
32#include <fcntl.h>
33#include <unistd.h>
34#include <dirent.h>
35#endif /* _WIN32 */
36#include <signal.h>
37
38#ifdef EVENT__HAVE_SYS_UN_H
39#include <sys/un.h>
40#endif
41#ifdef EVENT__HAVE_AFUNIX_H
42#include <afunix.h>
43#endif
44
45#include <event2/event.h>
46#include <event2/http.h>
47#include <event2/listener.h>
48#include <event2/buffer.h>
49#include <event2/util.h>
50#include <event2/keyvalq_struct.h>
51
52#ifdef _WIN32
53#include <event2/thread.h>
54#endif /* _WIN32 */
55
56#ifdef EVENT__HAVE_NETINET_IN_H
57#include <netinet/in.h>
58# ifdef _XOPEN_SOURCE_EXTENDED
59#  include <arpa/inet.h>
60# endif
61#endif
62
63#ifdef _WIN32
64#ifndef stat
65#define stat _stat
66#endif
67#ifndef fstat
68#define fstat _fstat
69#endif
70#ifndef open
71#define open _open
72#endif
73#ifndef close
74#define close _close
75#endif
76#ifndef O_RDONLY
77#define O_RDONLY _O_RDONLY
78#endif
79#endif /* _WIN32 */
80
81char uri_root[512];
82
83static const struct table_entry {
84	const char *extension;
85	const char *content_type;
86} content_type_table[] = {
87	{ "txt", "text/plain" },
88	{ "c", "text/plain" },
89	{ "h", "text/plain" },
90	{ "html", "text/html" },
91	{ "htm", "text/htm" },
92	{ "css", "text/css" },
93	{ "gif", "image/gif" },
94	{ "jpg", "image/jpeg" },
95	{ "jpeg", "image/jpeg" },
96	{ "png", "image/png" },
97	{ "pdf", "application/pdf" },
98	{ "ps", "application/postscript" },
99	{ NULL, NULL },
100};
101
102struct options {
103	int port;
104	int iocp;
105	int verbose;
106
107	int unlink;
108	const char *unixsock;
109	const char *docroot;
110};
111
112/* Try to guess a good content-type for 'path' */
113static const char *
114guess_content_type(const char *path)
115{
116	const char *last_period, *extension;
117	const struct table_entry *ent;
118	last_period = strrchr(path, '.');
119	if (!last_period || strchr(last_period, '/'))
120		goto not_found; /* no exension */
121	extension = last_period + 1;
122	for (ent = &content_type_table[0]; ent->extension; ++ent) {
123		if (!evutil_ascii_strcasecmp(ent->extension, extension))
124			return ent->content_type;
125	}
126
127not_found:
128	return "application/misc";
129}
130
131/* Callback used for the /dump URI, and for every non-GET request:
132 * dumps all information to stdout and gives back a trivial 200 ok */
133static void
134dump_request_cb(struct evhttp_request *req, void *arg)
135{
136	const char *cmdtype;
137	struct evkeyvalq *headers;
138	struct evkeyval *header;
139	struct evbuffer *buf;
140
141	switch (evhttp_request_get_command(req)) {
142	case EVHTTP_REQ_GET: cmdtype = "GET"; break;
143	case EVHTTP_REQ_POST: cmdtype = "POST"; break;
144	case EVHTTP_REQ_HEAD: cmdtype = "HEAD"; break;
145	case EVHTTP_REQ_PUT: cmdtype = "PUT"; break;
146	case EVHTTP_REQ_DELETE: cmdtype = "DELETE"; break;
147	case EVHTTP_REQ_OPTIONS: cmdtype = "OPTIONS"; break;
148	case EVHTTP_REQ_TRACE: cmdtype = "TRACE"; break;
149	case EVHTTP_REQ_CONNECT: cmdtype = "CONNECT"; break;
150	case EVHTTP_REQ_PATCH: cmdtype = "PATCH"; break;
151	default: cmdtype = "unknown"; break;
152	}
153
154	printf("Received a %s request for %s\nHeaders:\n",
155	    cmdtype, evhttp_request_get_uri(req));
156
157	headers = evhttp_request_get_input_headers(req);
158	for (header = headers->tqh_first; header;
159	    header = header->next.tqe_next) {
160		printf("  %s: %s\n", header->key, header->value);
161	}
162
163	buf = evhttp_request_get_input_buffer(req);
164	puts("Input data: <<<");
165	while (evbuffer_get_length(buf)) {
166		int n;
167		char cbuf[128];
168		n = evbuffer_remove(buf, cbuf, sizeof(cbuf));
169		if (n > 0)
170			(void) fwrite(cbuf, 1, n, stdout);
171	}
172	puts(">>>");
173
174	evhttp_send_reply(req, 200, "OK", NULL);
175}
176
177/* This callback gets invoked when we get any http request that doesn't match
178 * any other callback.  Like any evhttp server callback, it has a simple job:
179 * it must eventually call evhttp_send_error() or evhttp_send_reply().
180 */
181static void
182send_document_cb(struct evhttp_request *req, void *arg)
183{
184	struct evbuffer *evb = NULL;
185	struct options *o = arg;
186	const char *uri = evhttp_request_get_uri(req);
187	struct evhttp_uri *decoded = NULL;
188	const char *path;
189	char *decoded_path;
190	char *whole_path = NULL;
191	size_t len;
192	int fd = -1;
193	struct stat st;
194
195	if (evhttp_request_get_command(req) != EVHTTP_REQ_GET) {
196		dump_request_cb(req, arg);
197		return;
198	}
199
200	printf("Got a GET request for <%s>\n",  uri);
201
202	/* Decode the URI */
203	decoded = evhttp_uri_parse(uri);
204	if (!decoded) {
205		printf("It's not a good URI. Sending BADREQUEST\n");
206		evhttp_send_error(req, HTTP_BADREQUEST, 0);
207		return;
208	}
209
210	/* Let's see what path the user asked for. */
211	path = evhttp_uri_get_path(decoded);
212	if (!path) path = "/";
213
214	/* We need to decode it, to see what path the user really wanted. */
215	decoded_path = evhttp_uridecode(path, 0, NULL);
216	if (decoded_path == NULL)
217		goto err;
218	/* Don't allow any ".."s in the path, to avoid exposing stuff outside
219	 * of the docroot.  This test is both overzealous and underzealous:
220	 * it forbids aceptable paths like "/this/one..here", but it doesn't
221	 * do anything to prevent symlink following." */
222	if (strstr(decoded_path, ".."))
223		goto err;
224
225	len = strlen(decoded_path)+strlen(o->docroot)+2;
226	if (!(whole_path = malloc(len))) {
227		perror("malloc");
228		goto err;
229	}
230	evutil_snprintf(whole_path, len, "%s/%s", o->docroot, decoded_path);
231
232	if (stat(whole_path, &st)<0) {
233		goto err;
234	}
235
236	/* This holds the content we're sending. */
237	evb = evbuffer_new();
238
239	if (S_ISDIR(st.st_mode)) {
240		/* If it's a directory, read the comments and make a little
241		 * index page */
242#ifdef _WIN32
243		HANDLE d;
244		WIN32_FIND_DATAA ent;
245		char *pattern;
246		size_t dirlen;
247#else
248		DIR *d;
249		struct dirent *ent;
250#endif
251		const char *trailing_slash = "";
252
253		if (!strlen(path) || path[strlen(path)-1] != '/')
254			trailing_slash = "/";
255
256#ifdef _WIN32
257		dirlen = strlen(whole_path);
258		pattern = malloc(dirlen+3);
259		memcpy(pattern, whole_path, dirlen);
260		pattern[dirlen] = '\\';
261		pattern[dirlen+1] = '*';
262		pattern[dirlen+2] = '\0';
263		d = FindFirstFileA(pattern, &ent);
264		free(pattern);
265		if (d == INVALID_HANDLE_VALUE)
266			goto err;
267#else
268		if (!(d = opendir(whole_path)))
269			goto err;
270#endif
271
272		evbuffer_add_printf(evb,
273                    "<!DOCTYPE html>\n"
274                    "<html>\n <head>\n"
275                    "  <meta charset='utf-8'>\n"
276		    "  <title>%s</title>\n"
277		    "  <base href='%s%s'>\n"
278		    " </head>\n"
279		    " <body>\n"
280		    "  <h1>%s</h1>\n"
281		    "  <ul>\n",
282		    decoded_path, /* XXX html-escape this. */
283		    path, /* XXX html-escape this? */
284		    trailing_slash,
285		    decoded_path /* XXX html-escape this */);
286#ifdef _WIN32
287		do {
288			const char *name = ent.cFileName;
289#else
290		while ((ent = readdir(d))) {
291			const char *name = ent->d_name;
292#endif
293			evbuffer_add_printf(evb,
294			    "    <li><a href=\"%s\">%s</a>\n",
295			    name, name);/* XXX escape this */
296#ifdef _WIN32
297		} while (FindNextFileA(d, &ent));
298#else
299		}
300#endif
301		evbuffer_add_printf(evb, "</ul></body></html>\n");
302#ifdef _WIN32
303		FindClose(d);
304#else
305		closedir(d);
306#endif
307		evhttp_add_header(evhttp_request_get_output_headers(req),
308		    "Content-Type", "text/html");
309	} else {
310		/* Otherwise it's a file; add it to the buffer to get
311		 * sent via sendfile */
312		const char *type = guess_content_type(decoded_path);
313		if ((fd = open(whole_path, O_RDONLY)) < 0) {
314			perror("open");
315			goto err;
316		}
317
318		if (fstat(fd, &st)<0) {
319			/* Make sure the length still matches, now that we
320			 * opened the file :/ */
321			perror("fstat");
322			goto err;
323		}
324		evhttp_add_header(evhttp_request_get_output_headers(req),
325		    "Content-Type", type);
326		evbuffer_add_file(evb, fd, 0, st.st_size);
327	}
328
329	evhttp_send_reply(req, 200, "OK", evb);
330	goto done;
331err:
332	evhttp_send_error(req, 404, "Document was not found");
333	if (fd>=0)
334		close(fd);
335done:
336	if (decoded)
337		evhttp_uri_free(decoded);
338	if (decoded_path)
339		free(decoded_path);
340	if (whole_path)
341		free(whole_path);
342	if (evb)
343		evbuffer_free(evb);
344}
345
346static void
347print_usage(FILE *out, const char *prog, int exit_code)
348{
349	fprintf(out,
350		"Syntax: %s [ OPTS ] <docroot>\n"
351		" -p      - port\n"
352		" -U      - bind to unix socket\n"
353		" -u      - unlink unix socket before bind\n"
354		" -I      - IOCP\n"
355		" -v      - verbosity, enables libevent debug logging too\n", prog);
356	exit(exit_code);
357}
358static struct options
359parse_opts(int argc, char **argv)
360{
361	struct options o;
362	int opt;
363
364	memset(&o, 0, sizeof(o));
365
366	while ((opt = getopt(argc, argv, "hp:U:uIv")) != -1) {
367		switch (opt) {
368			case 'p': o.port = atoi(optarg); break;
369			case 'U': o.unixsock = optarg; break;
370			case 'u': o.unlink = 1; break;
371			case 'I': o.iocp = 1; break;
372			case 'v': ++o.verbose; break;
373			case 'h': print_usage(stdout, argv[0], 0); break;
374			default : fprintf(stderr, "Unknown option %c\n", opt); break;
375		}
376	}
377
378	if (optind >= argc || (argc - optind) > 1) {
379		print_usage(stdout, argv[0], 1);
380	}
381	o.docroot = argv[optind];
382
383	return o;
384}
385
386static void
387do_term(int sig, short events, void *arg)
388{
389	struct event_base *base = arg;
390	event_base_loopbreak(base);
391	fprintf(stderr, "Got %i, Terminating\n", sig);
392}
393
394static int
395display_listen_sock(struct evhttp_bound_socket *handle)
396{
397	struct sockaddr_storage ss;
398	evutil_socket_t fd;
399	ev_socklen_t socklen = sizeof(ss);
400	char addrbuf[128];
401	void *inaddr;
402	const char *addr;
403	int got_port = -1;
404
405	fd = evhttp_bound_socket_get_fd(handle);
406	memset(&ss, 0, sizeof(ss));
407	if (getsockname(fd, (struct sockaddr *)&ss, &socklen)) {
408		perror("getsockname() failed");
409		return 1;
410	}
411
412	if (ss.ss_family == AF_INET) {
413		got_port = ntohs(((struct sockaddr_in*)&ss)->sin_port);
414		inaddr = &((struct sockaddr_in*)&ss)->sin_addr;
415	} else if (ss.ss_family == AF_INET6) {
416		got_port = ntohs(((struct sockaddr_in6*)&ss)->sin6_port);
417		inaddr = &((struct sockaddr_in6*)&ss)->sin6_addr;
418	}
419#ifdef EVENT__HAVE_STRUCT_SOCKADDR_UN
420	else if (ss.ss_family == AF_UNIX) {
421		printf("Listening on <%s>\n", ((struct sockaddr_un*)&ss)->sun_path);
422		return 0;
423	}
424#endif
425	else {
426		fprintf(stderr, "Weird address family %d\n",
427		    ss.ss_family);
428		return 1;
429	}
430
431	addr = evutil_inet_ntop(ss.ss_family, inaddr, addrbuf,
432	    sizeof(addrbuf));
433	if (addr) {
434		printf("Listening on %s:%d\n", addr, got_port);
435		evutil_snprintf(uri_root, sizeof(uri_root),
436		    "http://%s:%d",addr,got_port);
437	} else {
438		fprintf(stderr, "evutil_inet_ntop failed\n");
439		return 1;
440	}
441
442	return 0;
443}
444
445int
446main(int argc, char **argv)
447{
448	struct event_config *cfg = NULL;
449	struct event_base *base = NULL;
450	struct evhttp *http = NULL;
451	struct evhttp_bound_socket *handle = NULL;
452	struct evconnlistener *lev = NULL;
453	struct event *term = NULL;
454	struct options o = parse_opts(argc, argv);
455	int ret = 0;
456
457#ifdef _WIN32
458	{
459		WORD wVersionRequested;
460		WSADATA wsaData;
461		wVersionRequested = MAKEWORD(2, 2);
462		WSAStartup(wVersionRequested, &wsaData);
463	}
464#else
465	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
466		ret = 1;
467		goto err;
468	}
469#endif
470
471	setbuf(stdout, NULL);
472	setbuf(stderr, NULL);
473
474	/** Read env like in regress */
475	if (o.verbose || getenv("EVENT_DEBUG_LOGGING_ALL"))
476		event_enable_debug_logging(EVENT_DBG_ALL);
477
478	cfg = event_config_new();
479#ifdef _WIN32
480	if (o.iocp) {
481#ifdef EVTHREAD_USE_WINDOWS_THREADS_IMPLEMENTED
482		evthread_use_windows_threads();
483		event_config_set_num_cpus_hint(cfg, 8);
484#endif
485		event_config_set_flag(cfg, EVENT_BASE_FLAG_STARTUP_IOCP);
486	}
487#endif
488
489	base = event_base_new_with_config(cfg);
490	if (!base) {
491		fprintf(stderr, "Couldn't create an event_base: exiting\n");
492		ret = 1;
493	}
494	event_config_free(cfg);
495	cfg = NULL;
496
497	/* Create a new evhttp object to handle requests. */
498	http = evhttp_new(base);
499	if (!http) {
500		fprintf(stderr, "couldn't create evhttp. Exiting.\n");
501		ret = 1;
502	}
503
504	/* The /dump URI will dump all requests to stdout and say 200 ok. */
505	evhttp_set_cb(http, "/dump", dump_request_cb, NULL);
506
507	/* We want to accept arbitrary requests, so we need to set a "generic"
508	 * cb.  We can also add callbacks for specific paths. */
509	evhttp_set_gencb(http, send_document_cb, &o);
510
511	if (o.unixsock) {
512#ifdef EVENT__HAVE_STRUCT_SOCKADDR_UN
513		struct sockaddr_un addr;
514
515		if (o.unlink && (unlink(o.unixsock) && errno != ENOENT)) {
516			perror(o.unixsock);
517			ret = 1;
518			goto err;
519		}
520
521		addr.sun_family = AF_UNIX;
522		strcpy(addr.sun_path, o.unixsock);
523
524		lev = evconnlistener_new_bind(base, NULL, NULL,
525			LEV_OPT_CLOSE_ON_FREE, -1,
526			(struct sockaddr *)&addr, sizeof(addr));
527		if (!lev) {
528			perror("Cannot create listener");
529			ret = 1;
530			goto err;
531		}
532
533		handle = evhttp_bind_listener(http, lev);
534		if (!handle) {
535			fprintf(stderr, "couldn't bind to %s. Exiting.\n", o.unixsock);
536			ret = 1;
537			goto err;
538		}
539#else /* !EVENT__HAVE_STRUCT_SOCKADDR_UN */
540		fprintf(stderr, "-U is not supported on this platform. Exiting.\n");
541		ret = 1;
542		goto err;
543#endif /* EVENT__HAVE_STRUCT_SOCKADDR_UN */
544	}
545	else {
546		handle = evhttp_bind_socket_with_handle(http, "0.0.0.0", o.port);
547		if (!handle) {
548			fprintf(stderr, "couldn't bind to port %d. Exiting.\n", o.port);
549			ret = 1;
550			goto err;
551		}
552	}
553
554	if (display_listen_sock(handle)) {
555		ret = 1;
556		goto err;
557	}
558
559	term = evsignal_new(base, SIGINT, do_term, base);
560	if (!term)
561		goto err;
562	if (event_add(term, NULL))
563		goto err;
564
565	event_base_dispatch(base);
566
567#ifdef _WIN32
568	WSACleanup();
569#endif
570
571err:
572	if (cfg)
573		event_config_free(cfg);
574	if (http)
575		evhttp_free(http);
576	if (term)
577		event_free(term);
578	if (base)
579		event_base_free(base);
580
581	return ret;
582}
583